Automated self-propelling endoscope

ABSTRACT

An improved mechanism for an automated self-propelling endoscope. The system augments the conventional “proximal-push” mechanism commonly used in colonoscopy with an innovative “distal-pull” mechanism. The distal-pull mechanism includes external application of a force at the proximal end of the endoscope that is translated into force that is exerted upon and moves the distal (leading) end of the scope further into the colon.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional PatentApplication Ser. Nos. 60/286,366, entitled “Mechanism For AutomatedSelf-Propelling Endoscope,” filed Apr. 26, 2001, and 60/290,658,entitled “Improved Mechanism For Automated Self-Propelling Endoscope,”filed May 15, 2001. The disclosures of these provisional patentapplications are incorporated herein by reference in their entireties.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to an improved mechanism for an automatedself-propelling endoscope.

2. Discussion of the Related Art

The flexible fiberoptic colonoscope has provided direct visualization ofthe inner surface of the entire colon, and has greatly influenced thediagnosis and treatment of colonic diseases over the past three decades.It is pervasively used throughout the U.S. and much of theindustrialized world. It provides information that is complementary tocommon radiologic, CT scan, MRI, and other sophisticated imagingscanning techniques in the diagnosis of colonic disease, and in manycircumstances it is considered to provide the most reliable, efficientand effective available tool. Via instruments inserted through channelsin the scope, a wide array of diagnostic and therapeutic instruments canbe used. However, a major impediment to colonoscopy is the long timethat often is required to examine the full length of the colon. Theintroduction of the scope is in a direction opposite to that effected bynormal peristaltic waves. Further, the tubular colon is tortuous andhighly flexible, and its walls often fail to direct and guide the scopeas it is moved into the colon. As the scope is manually propelled, itenters loops of colon that become “cul-de-sacs” which trap the leadingend of the scope, and prevent the desired retrograde movement of thescope through the lumen. Advancing the scope is reminiscent of attemptsto “push a chain or a flexible rope”. With only manual insertionefforts, progression of the distal end of the scope into the colon issuccessful for the first few short distances; but as the length ofpenetration increases and tortuous configurations of bowel need to benegotiated, the difficulties increase greatly, even with visualdirectional guidance of the tip of the scope. The endoscopist uses avariety of maneuvers to nudge the scope further, including repeatedlyrepositioning the patient (and the colon); utilizing gravity effects tomove the heavier leading end of the scope “downhill”; manipulating thescope against the bowel wall to round corners; applying pressure on theexternal abdomen; altering the rigidity of segments of the scope to moreeffectively translate push-effects distally; changing lumen size andconfiguration with air insufflation; etc. However much endoscopists dosucceed in traversing the entire colon, there is clearly need formechanisms to facilitate the process and to hasten its accomplishment.Many examinations require much time, and many are terminated before theexamination is complete. Thus, a mechanized process that would allowrapid retrograde propelling of the scope to the cecum would be of greatvalue. Colonoscopic examinations are costly, and part of this is due tothe amount of professional time required for the complete examination.In summary, were an automated mechanism available to facilitate rapidtraversal of the colon, it would increase both the effectiveness andefficiency of the wide range of diagnostic and therapeutic uses of theprocedure, and contribute to reducing the financial cost of theprocedure.

The essence of the problem is to develop a mechanized propelling systemthat is self-contained in the instrument that does not depend upon theexternal guidance effect of the surrounding highly flexible tubularbowel. Force to insert the colonoscope through the anus into the patientis simple and straightforward. What is needed is some array oftechnology that would simulate the actions of a “virtual hand” that waslocated in the lumen of the colon just ahead of the tip of theendoscope, and could grasp and pull the tip in the direction of thelumen toward the proximal colon. This is akin to a “Maxwell's demon'shand” that could and would “knowingly” act as needed.

An analogous problem exists for the small bowel endoscope (enteroscope).The small bowel is about 30 feet long and telescopes itself onintroduced instruments. It may take several hours for an enteroscope totraverse major portions of the small bowel. As a result, this is ararely used procedure.

Some characteristics of a conventional fiberoptic endoscope(colonoscope) are as follows: the scope is flexible in all directionsalong its central or longitudinal axis; it has a length of about 164 cmand a diameter of about 14.2 mm; the scope includes a fiberoptic viewingchannel and fiberoptic light pipes, and a depth of focus of about 5–100mm; controllable tip deflection of the scope is 180°/180° up/down and160°/160° right/left; and one or more air and water delivery channelsprovided in scope. In addition, a conventional scope typically includesone or more open channels for insertion of instruments for suction,biopsy, surgical incisions, injections, sonography, laser therapy, etc.

For reasons of safety, comfort to patients, and reduction of time andcosts of colonoscopic (and enteroscopic) procedures, a system whichwould allow automated retrograde introduction of endoscopes thatfollowed the course of the bowel lumen would be highly beneficial. Whenfully introduced in a timely fashion, existing fiberoptic colonoscopesare remarkably effective instruments for a variety of diagnostic andtherapeutic interventions. Over the past two decades, commercialdevelopments have produced small incremental improvements in theendoscopes and the instruments that are fed through their channels. Theone major innovation over recent years has been the introduction ofscopes by the Olympus Corporation that allows for selective increases ofrigidity of its segments; this has been demonstrated (Brooker, J. C. etal.: Gut; June, 2000: 46:801–805) to be very helpful to the“proximal-push” mechanism which has been and presently remains the mainmode for state-of-the-art propulsion of endoscopes. Nonetheless, manyinvestigators have recognized continuing need for and have attempted toaugment the proximal-push forces with other means to facilitatedelivering the endoscope to the entire target area.

The related art reveals a variety of approaches that have been taken toimprove the safety, efficacy, comfort, and efficiency of colonoscopy.Examples of some different approaches to enhance the design of anendoscope can be seen in U.S. Pat. Nos. 4,054,128, 4,389,208, 4,991,957,5,353,807, 5,482,029, 5,645,520, 5,662,587, 5,759,151, 5,819,736,5,906,591, 5,916,146, 5,984,860, 5,996,346, 6,162,171, 6,293,907,6,309,346, 6,315,713 and 6,332,865. The disclosures of these patents areincorporated herein by reference in their entireties. The efforts todeliver the working end of endoscopes to the sites required for completeexamination or treatment of the colon and small bowel have includedseveral different modalities for physically transporting the endoscopeinto the patient. Yet, the clinical state-of-the-art for colonoscopy hasrested on the decades old “proximal-push technology” as its mainstay,with the recent major improvement offered by introduction of scopes bythe Olympus Corporation that allow for selective increases of rigidityof its segments. Otherwise, technical improvements of colonoscopesthemselves have been small and incremental; nonetheless, the net resultof the numerous small improvements over the years is the currentavailability of colonoscopes that are technical marvels. Illuminationand visual fields; flexibility of the body; universal flexibledirectional control of the distal end of the scope; air and water jetdelivery channels; one or more small to large channels for insertion ofinstruments to provide suction, biopsy, injections, incisions,sonography, laser therapy, etc., etc. attest to the great versatilityand effectiveness of this modality in management of gastrointestinaldisease. Indeed, the proliferation of many sophisticated instrumentswhich are introduced via the scope's channels has so greatly increasedthe usefulness of colonoscopy that the lack of more major improvementsin its own intrinsic technology has been comfortably tolerated.

What are the important improvements in current state-of-the-artcolonoscopy that cry out for attention and solution? Mostly they revolveabout the ease, comfort, safety and rapidity of introduction andtraversing of the entire colon for the intended diagnostic and/ortherapeutic purposes. By synthesizing the information in the manypatents listed above, the following points can be observed:

1. Major efforts have been expended and are under way to deviseinnovative methods for transporting the endoscope to where it needs tobe with appropriate control, timeliness, safety, ease and comfort; thisconfirms the importance of these continuing needs.

2. The proximal-push mechanism is central and necessary for propelling acolonoscope, but it is not fully sufficient. Many investigators havedeliberately attempted to augment the proximal-push with other forces topropel the colonoscope to meet the described needs.

3. It is becoming progressively more difficult to clearly identify theboundaries between technical support of medical/surgical clinicalgastroenterology and the robotics supporting minimally invasive surgery(MIS).

4. In the attempts to innovate more effective endoscopic instruments,some investigators have developed instruments that come to look less andless like current endoscopes. Many have substituted new complicatedtechnologies that are not superior to current colonoscopes to supplantexisting scopes rather than creating new systems that can utilize thevery mature, superb existing scopes. Many proposals rely on moving partsgaining traction against the bowel wall, or pushing on the wall, or thatuse pneumatic suction to adhere to the wall, all of which may alter orinjure the mucosa. Others significantly increase the bulk of instrumentsthat are inserted into the colon.

From these disparate considerations, a new vision crystallized: Animproved propelling mechanism for the colonoscope should not sacrificeany meaningful characteristics of today's state-of-the-art colonoscope.This dictates that an innovative propelling mechanism must be engraftedupon today's existing scopes; an innovative propelling mechanism shouldbe implemented which requires no or relatively few structural changes ofexisting colonoscopes, where any changes are so minimal as not todisturb any of their present attributes.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide animproved mechanism for an automated self-propelling endoscope (“scope”)that is highly effective in propelling the scope within the bowels.

Another object of the present invention is to provide a highly effectiveself-propelling endoscope with minimal alteration to the scope design.

A further object of the present invention is to provide a propellingmechanism for the scope that enhances the classical “proximal-push”mechanism conventionally utilized in the colonoscope art.

The aforesaid objects may be achieved individually and/or incombination, and it is not intended that the present invention beconstrued as requiring two or more of the objects to be combined unlessexpressly required by the claims attached hereto.

According to the present invention, a self-propelling endoscope systemis established that is capable of converting a colonoscope into anautomated self-propelling colonoscope. In particular, the system of thepresent invention is capable of converting a standard, unmodifiedcommercial colonoscope into an automated self-propelling colonoscopewith no (or minimal) alteration to the colonoscope itself.

The system augments the classical “proximal-push” mechanism with a“distal-pull” mechanism. The proximal-push mechanism consists simply ofserial insertions of lengths of the scope through the anus into thepatient. The distal-pull mechanism ultimately consists of externallyapplying force at the proximal end of the scope that is translated intoforce that is exerted upon and moves the distal (leading) end of thescope further into the colon. This force translation includes: 1)controlled anchoring of the loop of the scope between sites at theproximal operating end, and immediately external to the anus; 2) aninserted flexible wire obturator having an external wall releasableconnector (e.g., a circumferential inflatable balloon) located justproximal to the scope's flexible leading segment to temporarily bond theleading end of the obturator with the leading end of the body of thescope; and 3) stationary racks with couplings which grasp and eitherhold stationary, or electromechanically move the scope body through theanus into the colon, and in controlled sequence apply the moving forceto the proximal end of the obturator. Various combinations and sequencesof these actions result in specific patterns of scope locomotion that,when integrated and cyclically repeated, facilitate the automatedself-propelling mechanism for the endoscope. In other embodiments, minormodifications of the colonoscope provide other mechanisms accomplishingthe propelling mechanism. All propelling movements, as described indetail below, may also be performed manually by assistants to theendoscopist.

The above and still further objects, features and advantages of thepresent invention will become apparent upon consideration of thefollowing definitions, descriptions and descriptive figures of specificembodiments thereof wherein like reference numerals in the variousfigures are utilized to designate like components. While thesedescriptions go into specific details of the invention, it should beunderstood that variations may and do exist and would be apparent tothose skilled in the art based on the descriptions herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an elevated side view in partial section of a self-propellingendoscope system according to the present invention.

FIG. 1B is a cross-sectional view taken along lines 1B—1B of theendoscope of FIG. 1A.

FIGS. 2A–2C are elevated side views in partial section of the system ofFIG. 1A showing the “distal-pull” effect exerted from the proximal endof the endoscope.

FIG. 3 is a side view in partial section of another embodiment of aself-propelling endoscope system according to the present invention.

FIG. 4 is a side view in partial section of the system of FIG. 3 showinga completed cycle of strong “proximal-push” and “distal-pull” effects.

FIGS. 5A and 5B are side views in partial section of the system of FIG.3 showing operation of the clamps at the Rack Two location of thesystem.

FIG. 6 is a side view in partial section of the system of FIG. 3 showingopposing forces acting upon the EXT-obturator of the system during a“proximal-push” and “distal-pull” cycle.

FIG. 7 is a side view in partial section of the system of FIG. 3 showingthe configuration of the endoscope and obturators after eight cycles ofmovement by the system.

FIGS. 8A–8F are views in partial section of alternative embodiments of aself-propelling endoscope system according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In an exemplary embodiment of a self-propelling endoscope system of thepresent invention includes modification of existing flexible obturators,and use of external automated controlling mechanisms, but requires nomodification of the endoscope itself. Other embodiments involve slightmodification to the endoscope as described below.

FIGS. 1A and 1B illustrate schematic sagittal (i.e., longitudinalcross-section) and cross-sectional views of the endoscope. The sagittalsection depicts a flexible colonoscope laid out in a linear fashion. Itsessential components are labeled and shown in FIG. 1A. FIG. 1B is aschematic cross-sectional view. Letters “A” through “J” are labels toidentify the following components:

A). Outer wall of colonoscope.

B). Wall of “obturator channel” forming the lumen (diameter preferablyin the range of about 3.8–5 mm) through which wire obturators arepassed. The obturator channel wall is integrally attached to the outerwall of the colonoscope such that movement of the obturator channel wallforces corresponding movement of the scope. To allow clarity ofillustration, the size of this channel is greatly exaggerated relativeto the cross-section of the remaining parts of the endoscope. During theautomated propelling phase, this channel contains the insertedobturators whose manipulations effect the forward movement of theendoscope. However, after the scope has been fully introduced, theseobturators are withdrawn, and the full channel is available for suctionor for insertion of any of the numerous diagnostic and therapeutic toolsavailable.

C). Wall of outer coiled wire obturator or EXT-obturator, illustrated asa dotted line. The EXT-obturator is highly flexible along its linearaxis, it is non-distensible, and its total length is negligiblyexpandable or compressible. It is the vehicle mediating the propellingsystem described in detail below. Its distal end protrudes beyond thedistal end of the scope into the colon, and can serve as a suctionchannel throughout the procedure.

D). Wall of inner coiled wire obturator or INT-obturator, illustrated asa solid line. It also is highly flexible along its linear axis, isnon-distensible, and its length neither expandable nor compressible. Ofthe two obturators used in the propelling system, the INT-obturator hasthe smaller diameter, and is inserted through the lumen of theEXT-obturator. As seen in the cross-sectional view of FIG. 1B, theINT-obturator has a lumen that can be used for additional optionalsuction during the propelling phase. It has no role in the propellingmechanism, and, optionally, may not be included during propelling of thescope as described below. The lumen of the INT-obturator is not depictedin FIG. 1A; rather, the INT-obturator is represented as one single wideline to facilitate visualizing the relationships between the twoobturators.

E). Fiberoptic channel and other functional components. Together, all ofthese components are rendered as a single dashed line in the figures.The fiberoptic channel is located in the space within the colonoscope'souter wall, and is external to the obturator channel. The several otherfunctional elements that are similarly located in this space which arenot separately depicted graphically are represented by this same dashedline; included are channels for fiberoptic light-pipes; guide-wires foruniversal directional flexing of the leading tip of the scope; airinflation; and water inflation. Together, these “E” elements make up thebulk of the cross-sectional content of the endoscope. Consider all ofthese elements as a bundle that constitutes the major operating end ofthe scope held by the endoscopist. The “E” bundle is separated from theobturator channel and its contents near the proximal end of the scope.The curved pathway of the dashed line is meant to convey the physicalseparateness and mobility of the operating end of the scope, so that theendoscopist can integrate and control the usual tasks with thoseassociated with the automated propelling operation. To facilitatedescription of the system, the size of the obturator channel and itscontents is grossly exaggerated in the figures, and the proximal end ofthe obturator channel is depicted in straight continuity with theremaining portion throughout the length of the scope. However, theobturator channel may include other configurations (e.g., this channeltypically includes a small side channel coming off of the larger body ofthe endoscope).

F). Flange secured to the proximal end of the scope and the proximal endof the obturator channel. This flange, when grasped and held in a fixedposition by a coupling mechanism (dotted line) of Rack One (I)stabilizes the spatial position of the proximal end of the automatedpropelling mechanism.

G). Flange secured to the proximal end of the EXT-obturator. Thisflange, when grasped and held in a fixed position by another couplingmechanism (dotted line) of Rack One, controls the movement of theEXT-obturator. A motor within Rack One exerts intermittent controlledtiming of controlled variable force on the flange to move theEXT-obturator forward (i.e., from left to right in FIGS. 1A and 1B) orbackward (i.e., from right to left in FIGS. 1A and 1B).

Since the INT-obturator serves as an optional suction conduit, theoperator may choose to manually control its placement and movement. Ifdesired, an alternative is to couple the EXT-obturator and theINT-obturator to maintain a constant spatial relationship therebetween.

I). Rack One. Rack One sits upon and is strongly fastened to a platformor table (not shown) located adjacent to the proximal end of theendoscope. This stabilizes the proximal region of the scope distal towhere the endoscopist holds its major operating end. Rack One has twopotential coupling mechanisms attached to flanges F and G. One couplingmechanism couples to flange F and holds the obturator channelimmobilized at a fixed point in space. The other coupling mechanismcouples to flange G and holds the EXT-obturator and, as programmed,either holds it motionless, or as force is applied, moves the obturatorforward. Rack One further includes a controller and/or other suitablecomponents (e.g., motors or other electromechanical components) tocontrol movement of the coupling mechanisms thereby effecting automatedmovement of the EXT-obturator and the obturator channel.

J). A mechanism to reversibly bond the distal end of the EXT-obturatorwith the distal end of the scope's channel wall. In an exemplaryembodiment, this is accomplished by inflation of a circumferentialcylindrical balloon on the outer wall of the EXT-obturator.(Alternatively, a series of closely adjacent smaller balloons may beused to avoid this segment of the scope losing its flexibility as theballoons are inflated).

A “distal-pull” effect exerted from the proximal end of an endoscope ina simplified linear configuration model is now described in relation toFIGS. 2A–2C. FIGS. 2A–2C illustrate, in a simplified model and a linearconfiguration, the steps by which manipulation of the EXT-obturator canexert a distal-pull effect on a flexible endoscope. FIG. 2A shows theendoscope lying on a flat surface in a linear configuration. In FIG. 2Athe two coupling mechanisms of Rack One are shown as grasping andholding stationary the proximal end flanges F and G of the obturatorchannel wall and the EXT-obturator, respectively. Releasable bonding ofthe distal ends of the EXT-obturator and the obturator channel isprovided with the inflated balloon J. As previously noted, thisreleasable bonding may be provided with any other suitable mechanism.

In FIG. 2B, the Rack One instructions are to release the flange to theproximal end of the scope and to grasp and exert forward (i.e., left toright) force on the EXT-obturator flange, shown by the arrow in the RackOne box, to move it one unit distance. Because the distal end of theEXT-obturator is bonded to the channel wall, the forward thrust on theEXT-obturator pushes the distal end of the obturator channel forwardalong with the entire endoscope which is integrally attached to it.Thus, the effect is the same as manually grasping the distal end of thescope and pulling it forward (i.e., to the right as illustrated in FIGS.2A–2C). In this linear configuration, it is easy to see that forceexerted at the proximal end of the scope (i.e., on the flange of theEXT-obturator) simulates the effects of an external pulling forceexerted on the distal end of the scope. To use this effect in areal-life endoscopy context, a major challenge involves devising asystem in which such a “distal pull” can be effected when the scope isnot in a linear configuration, but rather follows multiple curvesoutside the body and as it moves through the bowel. As the scope movesforward (i.e., to the right in FIGS. 2A–2C), the INT-obturator, havingbeen held motionless, no longer protrudes beyond the distal end of thescope.

In FIG. 2C, the Rack One instructions are to hold the flanges of theproximal ends of the scope and EXT-obturator motionless, and manuallythe INT-obturator is moved one unit distance forward. This completes onefull cycle, re-establishes the spatial relationships between theendoscope and the two obturators as illustrated in FIG. 2A, and theentire scope has been moved forward one unit distance (i.e., compare thepositioning of the endoscope in FIGS. 2A and 2C).

Another embodiment of the present invention is depicted in FIGS. 3–7.This system is similar to the system of FIGS. 1–2 and includes a RackTwo K, which is similar in design and operability to Rack One. Each RackOne and Rack Two includes coupling mechanisms as described below toeffect movement of the EXT-obturator C and obturator channel B asdescribed below. This system also illustrates a “distal-pull” effectexerted from the proximal end of an endoscope in a real-lifeconfiguration involving tortuous path rather than linear movementconfigurations. To explain the “distal-pull” effect in this system, itis necessary to (A) describe the operational configuration of theendoscope in actual practice; (B) detail the functions of Rack One andRack Two of the system as to their respective roles in contributing toforward (i.e., left to right as illustrated in FIGS. 3–7) motion of theendoscope; and (C) describe integration of the various components in thesystem to accomplish the automated propelling motion.

A. Operational Configuration of the Endoscope in Actual Practice

The operational configuration of the endoscope in actual practice isrepresented in FIG. 3. The proximal controls of the endoscope fordirecting the distal tip, water and air insufflation, fiberoptic lightpipes, and the optical channel for visualizing the gut are bundledtogether (depicted as dashed line E) and held by the endoscopist. Theproximal end of the obturator channel F is held in a fixed position bythe Rack One coupling mechanism. This defines the beginning of a longloop formed initially between the operating proximal end of the scopeand the distal end of the scope that is manually inserted through theanus into the distal colon. The stability of the proximal end of thescope is enhanced by a firm coupling to a rigid ring L through which thescope passes. The scope is also firmly coupled and firmly supported by asecond ring N through which the scope passes. Operationally, the end ofthe loop of the scope is at the anchored point M. The rings L and N arerespectively coupled (see dashed lines in FIG. 3) to Rack One I and RackTwo K.

Rack Two provides stationary stable support for the colonoscope beyondthe loop by two sets of clamps, disposed at point M in FIG. 3. The twosets of clamps work alternately as described below. At all times througha cycle, one or the other of the clamp sets is holding and controllingthe location of the body of the scope in this region. At the beginningand end of each cycle, one or the other set of clamps fixes theendoscope at point M. Together, the coupling mechanisms coupled toflange F and point M provide two stationary points in space at which theproximal end of the obturator channel and the immediate post-loopcolonoscope are continuously anchored, allowing for complete control ofthe length of the loop between them, and assuring that there is noincrease in the length of the loop when forces are applied to the scope.The importance of this for the propelling mechanism is described below.

Consider FIG. 3 as the baseline stage at which the endoscopist hasmanually advanced the endoscope under visual guidance as far into therectosigmoid area as is practical, and where use of the automatedpropelling activity is then considered. The EXT-obturator is fullyinserted into the scope channel. A fine plastic tube extending along itsentire length allows its distally located balloon J (or other suitablebonding mechanism) to be inflated from an external position. Inflationof the circumferential balloon serves as a circumferential wedge in thespace between the EXT-obturator and the obturator channel, therebybonding the two. When the EXT-obturator is moved, it drags the distalend of the scope with it. Comparison of FIG. 4 with FIG. 3 shows theeffects of one full propelling cycle. Note the limited areas ofbackground gridlines that allow easy comparison of the movements andpositions of the colonoscope and the obturators as cycles of thepropelling mechanism are activated and changes are shown in sequentialfigures.

B. Detailed Description and Functions of Rack One and Rack Two forPropelling the Eendoscope Forward

FIG. 3 depicts Rack One and Rack Two at the beginning of a propellingcycle. Rack One sits upon and is strongly fastened to a platform ortable located adjacent to the proximal end of the endoscope. It has twopotential coupling mechanisms, each designated by a dotted line whenactive. In FIG. 3, the vertical line attached to the coupling of theproximal end of the obturator channel F establishes a fixed and stablelocation for it; the proximal end of the obturator channel does notchange its location during the entire operation of the automatedpropelling operation. This stability is enhanced by a similar firmcoupling to rigid ring L through which the scope passes. Beyond the ringL is the loop that consists of the major length of the endoscope. Thecoupling mechanism at point G, including a pair of clamps, holds theEXT-obturator stationary with respect to Rack One I.

Electrical motors of Rack One provide variable controlled levels offorce to be exerted on the coupling of the obturator. The criticaleffects of forward (i.e., left to right) force exerted on theEXT-obturator are described as follows.

As illustrated in FIGS. 5A and 5B, Rack Two K sits upon and is stronglyfastened to a platform or table located adjacent to the patient's analinsertion area. Rack Two controls two sets of alternating clamps atpoint M. Specifically, FIG. 5A illustrates the movements of one set oftwo clamps located at 12 o'clock and 6 o'clock on the circumference ofthe endoscope at point through the course of one time cycle. At thebeginning of a first cycle, the two clamps of the first set grasp thetop and bottom surfaces of the colonoscope. Force is exerted on the setof clamps, via Rack Two, to move them from the proximal, or left, to thedistal, or right, position (as shown by the arrow in the Rack Two box ofFIG. 5A), thereby moving the scope forward into the patient by one unitlength (also indicated by dotted arrows in FIG. 5A). The clamps arereleased at the end of the first cycle. During the second cycle, thereleased clamps are returned to their original proximal position. In thethird cycle, the steps of the first cycle are repeated.

FIG. 5B summarizes actions in the second cycle in which two clamps ofthe second set at point M, located at 3 o'clock and 9 o'clock on thecircumference of the endoscope, perform similarly. That is, at thebeginning of the second cycle, these two clamps grasp the two sides ofthe colonoscope. For purposes of convenience, the obturator channelwall, INT- and EXT-obturators and bundle of wires E are not shown inFIG. 5B. Force is applied, via Rack Two, to move these clamps from theproximal to the distal position (as shown by the arrow in the Rack Twobox of FIG. 5B), thereby moving the scope forward into the patient byone additional unit length. The clamps are released at the end of thesecond cycle. During the third cycle, the released clamps are returnedto their original proximal position. In the fourth cycle, the steps ofthe second cycle are repeated. Thus, the two alternating sets of clampsserve both to move the scope and to be a continuous anchor of theendoscope at point M at the end of each cycle. They provide a smoothforward motion of the scope into the patient. Variable controlled levelsof force to be exerted on the sets of clamps are provided by electricalmotors of Rack Two.

A similar coupling-clamp mechanism is used to move the EXT-obturatorforward by force applied to its proximal end at point G (see FIG. 3),resulting in forward (i.e., left to right) motion of the scope. Becauseof the smaller diameter of the EXT-obturator, the two sets of clamps aremounted on adjacent serial segments rather than on different parts ofthe circumference of the same segment.

C. Integration of the Various Components of the System to Accomplish theAutomated Propelling Motion.

In the system described above, the transit of the endoscope from thedistal toward the proximal colon is effected through two sets ofactions: one is the “proximal-push” effect and the other is the“distal-pull” effect. The simultaneous combined use of automatedproximal-push and distal-pull mechanisms greatly facilitates rapidtransit of the scope from the distal colon to the cecum.

Initially, the proximal-push effect is begun by manually inserting thescope through the anus into the rectum and pushing it into the sigmoidarea. With only manual insertion efforts, progression of the distal endof the scope into the colon is successful for the first few shortdistances; but as the length of penetration increases and tortuousconfigurations of bowel need to be negotiated, the difficulties mayincrease meaningfully, even with visual directional guidance of the tipof the scope. The endoscopist uses a variety of maneuvers to nudge thescope further, including repeatedly repositioning the patient (and thecolon); utilizing gravity effects to move the heavier leading end of thescope ‘downhill”; manipulating the scope against the bowel wall to roundcorners; applying pressure on the external abdomen; altering therigidity of segments of the scope to more effectively translatepush-effects distally; changing lumen size and configuration with airinsulation; etc. However much endoscopists do succeed in traversing theentire colon, there is clearly need for mechanisms to facilitate theprocess and to hasten its accomplishment.

Consider the isolated proximal-push effect of the two sets of clampscontrolled by Rack Two at point M. The alternation of the two sets ofclamps essentially provides a controlled automation of the usual manualinsertion efforts described above. However, even using the supportivemanipulations described above, successful negotiation of the entirecolon by this method alone often is problematical.

Consider one cycle of activity of the propelling system in which theproximal-push effect of Rack Two is dominant and strong, and there alsois a strong distal-pull effect of Rack One. Comparison of FIG. 3 as theinitial state prior to the cycle, with FIG. 4 as the end of the cycleallows analysis of the interacting changes that occur. The Rack Twoclamps at point M close firmly on the endoscope; left to right force isapplied by the Rack Two coupling mechanism, moving the clamps one unitlength from their proximal to their distal positions; and the terminalportion of the endoscope likewise is pushed one unit distance into thepatient. At the end of the cycle, the second set (3 o'clock and 9o'clock) of clamps close firmly on the scope at point M. Because pointsF and M are fixed in space, the one unit length of the endoscope'sadvance into the patient (seen on the grid) requires shortening of boththe descending and ascending limbs of the loop by one-half unit distanceeach (easily seen by the rise of the trough of the loop by one-half of agrid length in FIG. 4).

Simultaneously, there is a strong Rack One distal-pull effect. Such aneffect is symbolized in FIG. 4 by the arrow in the Rack One boxrepresenting left to right force applied to the clamps at point Gholding the EXT-obturator during the cycle. The simultaneous forceapplied to the EXT-obturator creates a potentiating distal-pull effect;the two forces applied simultaneously accomplish the forward movementmore easily. Importantly, the distal-pull effect additionally moves theleading end of the scope further into the bowel, and straightens outredundant and loose tortuous loops of the scope lying in the colon.

Next, consider one additional cycle of activity in which both theproximal-push effect of Rack Two and the distal-pull effect of Rack Oneare both strong. Comparison of FIG. 4 as the initial state prior to thissecond cycle with FIG. 6 as the end of the cycle, shows another unitdistance advance of the scope, and additional shortening of both limbsof the scope's loop (FIG. 6). It is important to understand theinteractions between the proximal-push and distal-pull mechanisms.Consider the consequences of strong constant force applied to move theEXT-obturator coupler of Rack One forward (i.e., to the right),symbolized by the left-to-right arrow applied to the coupler in FIG. 6.As the entire EXT-obturator is moved forward by this force, the entiredistal segment of the endoscope to which it is integrally bound alsomoves to the right. Thus, this set of forces manifests the desired“distal-pull” effect on the distal end of the scope. Under theendoscopist's visual guidance and manipulation of the scopes tip'sdirection, the leading end of the scope is “pulled” into the open lumenpathway before it. The “distal-pull” effect of Rack One is simultaneouswith and complementary to the “proximal-push” effect of Rack Two.

Further, consider the movement and spatial location of the EXT-obturatorduring this cycle ending as depicted in FIG. 6. During the cycle twoopposing sets of forces act upon the sets of clamps at point G,represented by the two opposing arrows in FIG. 6. The first force,indicated by the left-to-right arrow, represents displacement to theright as left-to-right force is exerted on it to create the“distal-pull” effect. An opposing second set of forces (theright-to-left arrow) is dictated by the requirement that, at the end ofeach cycle, the spatial relationship of the EXT-obturator to theproximal end of the obturator channel must be the same as at thebeginning of the cycle. This opposing set of forces tends to return theRack One coupler toward its initial position. Briefly, the opposingforces can be explained as follows. At the end of cycle two, thecombined Rack Two “proximal-push” and the Rack One “distal-pull” effectshave moved the endoscope one unit distance into the patient. Becausepoints F and M are fixed in space, the one unit length of theendoscope's advance into the patient in this cycle (seen by changes ofposition on the grid in FIG. 6) requires another shortening of both thedescending and ascending limbs of the loop by one-half unit distanceeach. Since the length of the EXT-obturator (from point G proximally toits distal end) is constant, and its distal end is bonded to the distalend of the scope so that it cannot move beyond the distal end of theobturator channel, the shortening of the loop (driven by theproximal-push mechanism) forces the EXT-obturator coupling to returntoward its original starting position. Because of the temporalcoordination of the Rack Two proximal-push and the Rack One distal-pulleffects, it is possible to greatly vary the amount of left-to rightforce applied to the EXT-obturator to obtain the desired distal-pulleffect while causing only small amounts of displacement of theEXT-obturator coupler clamps. Thus, the mix of forces providingproximal-push and distal-pull effects can be varied greatly. The timingand magnitude of the two automated applied forces may be controlled bythe endoscopist.

Generally speaking, the Rack Two effect has greater influence on movingthe proximal segments of the scope, while the Rack One effect hasgreater influence on moving the distal segment of the scope. Returningto an earlier analogy, the Rack Two effect in isolation mimics thedifficulty of trying to push a flexible rope from its proximal end. Thecombined Rack One and Rack Two effect is analogous to moving a rope bysimultaneously moving its proximal and distal ends in a coordinatedfashion. The proximal-push and the distal-pull mechanisms jointlycontribute to the forward propelling motion: additionally, thedistal-pull mechanism further advances the tip of the scope as itstraightens tortuous and redundant curves of the scope in the colon.

During the cycle, the INT-obturator may be moved in and out manually andused for suction; or it may be removed and not used.

In some circumstances, the Rack One effect may be exerted alone. Thatis, the Rack Two proximal-push effect is not activated and simply holdsthe scope motionless at the point M location while forward pressure isexerted on the EXT-obturator coupling at point G to create a distal-pulleffect. Such a maneuver further advances the tip of the scope bytightening loose and tortuous configurations of the scope relative tothe bowel in which it lies between the anus and the distal tip of thescope.

Occasionally, this mechanism is used in reverse. In many circumstances,the endoscopist cannot identify the direction of the colon lumen; itsappearance is confounded with cul-de-sacs or convolutions of loops ofbowel segments. To address this problem, it is necessary to pull theendoscope partially out, and then explore during re-entry. By combininga static proximal-push mechanism (i.e., continuous anchoring of thescope at point M) with pulling or backward (i.e., right to left)movement of the proximal end of the EXT-obturator, the distal end of theEXT-obturator may be partially withdrawn, carrying with it the bondeddistal segment of the endoscope. This avoids a major withdrawal byexternally pulling the entire scope through the anus. It providesadditional operational versatility to the colonoscopist for reaching thececum.

The system illustrated in FIGS. 3–7 for automated propelling of anendoscope through the colon is based on the synergistic use of the twomechanisms described above. The first mechanism consists of repeatedcycles, mediated through Rack Two, providing a “proximal-push” mechanismthat progressively moves the endoscope through the anus into the colon.The duration of each cycle and the length of the segment of theendoscope moved forward in each cycle (hence, the linear rate of thescope's introduction into the patient) can be varied, and are under thecontrol of the endoscopist. Additionally, the amount of Rack Two forceapplied in the cycles to effect the scope's forward movement through theanus is variable and controllable, so that sufficient but not excessivelevels of force can be used.

The second mechanism, mediated through Rack One, provides for forceapplied to the proximal end of the EXT-obturator to be translatedthrough the obturator channel and serve as a simulated “distal-pull”effect on the distal end of the scope. Rack One cycles are temporallycoordinated with Rack Two cycles. In one of the examples describedabove, both proximal-push and distal-pull effects were strong. Inanother example described above, the distal-pull effects were used alonewhen the scope within the colon has loose, redundant tortuosities andcurvatures that need to be straightened. The endoscopist can control therelative strengths of both methods used for propulsion. Given that theproximal-push has a predominant effect on the more proximal portion ofthe scope, and that the distal-pull has a more predominant effect on thedistal portion of the scope, clinical experience will allow theendoscopist to vary the uses of the two mechanisms'characteristics atsequential stages of the procedure as he or she fashions the mosteffective use of these capabilities. The flexibility to do so is builtinto the system.

In FIGS. 3–7, two cycles of the proximal-push in combination with thedistal-pull effects have been described. Repeating cycles in a mannerdescribed above allows the scope to traverse the colon from therectosigmoid area to the cecum. In FIG. 7, a schematic illustration ofthe system is depicted after six additional cycles have occurred and thescope has negotiated curves to advance a total of 8 unit lengths. Pointsare labeled in FIG. 7 to depict the following travel path for the scope:“0” indicates where the end of the scope was at the point of thebeginning of the first cycle; “1, 2, 6 and 8” indicate locations of thedistal end of the scope after completion of corresponding automatedpropelling cycles. Each cycle results in one unit length progression ofthe distal end of the scope, indicated approximately as the distancebetween grid lines depicted in FIG. 7. Comparison of FIG. 3 (prior tothe first automated cycle) with FIG. 7 (after completion of eightautomated cycles) shows that the scope's forward progression of eightunit lengths through the colon occurs at the expense of the loop whosedescending and ascending limbs each are four unit lengths shorter.

Of critical importance is the system's behavior as the leading tip ofthe endoscope approaches curved loops of colon. As the endoscopistvisualizes such curves, the direction of the tip of the scope ismanipulated so that its linear axis lines up with the linear axis of thegut lumen immediately ahead of it. Since the effective site of thedistal-pull effect is very close to the terminal end of the scope, itsthrust should support forward movements of the scope into the lumenopening ahead of it; repeated small steps may be needed to negotiatesevere curves. The resistance of the bowel wall to deformation may berecruited to help guide the scope around such curves. Additional cyclesadd to the progression of the endoscope, until it reaches the cecalarea. Once reached, the endoscopist can disengage the automatedpropelling system, and revert to the customary procedures forexamination of the colon as the colonoscope is manually withdrawn. As itis withdrawn, the obturator channel is available for insertion of any ofthe diagnostic or therapeutic tools needed as determined by theendoscopist's findings.

It is important to avoid application of excessive forces. Since movementof the endoscope is largely effected by means of force exerted throughRack One and Rack Two motors, mechanisms may be instituted to preventexcessive force being exerted on the colon. For example, pressuresensors on the leading tip of the endoscope and/or of the obturators canbe programmed to alarm the operator, and to interrupt continuation ofthe propelling mechanism when specified pressure levels are exceeded.

Several alternative technologies to support the “distal-pull” effect areillustrated in FIGS. 8A–8F. In FIG. 8A, the releasable bonding mechanismJ includes a retractable flange that is extruded from the distal wall ofthe obturator channel into the lumen against which the EXT-obturatorabuts. Forward or left-to-right force applied to the proximalEXT-obturator coupling is translated to, and moves the distal tip of thescope forward. Creating the retractable flange entails engineeringchanges of the colonoscope.

In FIG. 8B, a gap in the distal wall of the obturator channel serves asa receptor for a stent-like protrusion from the distal end of theEXT-obturator. The stent-like protrusion can be controlled by theendoscopist to engage the gap and thus serves as the releasable bondingmechanism J and a functional alternative to the retractable flange ofFIG. 8A.

In FIG. 8C, the releasable bonding mechanism J includes a tip on theEXT-obturator that abuts extruded flanges in the distal obturatorchannel. Alternative force mechanisms can also be used. For example,once the tip of the EXT-obturator is abutted to the retractable flanges,the tip of the EXT-obturator can have force applied via an expandablesection (i.e., the large dashed extension depicted in FIG. 8C)controlled from the outside by the endoscopist. The force exerted couldbe from an electronically controlled solenoid or linear activator; orfrom high-pressure injection of gas or water through a fine tube runningthe length of the obturator.

FIG. 8D depicts a semilunar or rectangular shaped metal flap which isinstalled on the leading edge of the scope and serves as the releasablebonding mechanism J and a substitute for the retractable flange of FIG.8A. Its position would line up directly with a dedicated obturatorlumen, so that the transmission of force function of the EXT-obturatorwould be exerted directly on it. It could be small enough so that therewould be no compromise of other needed endoscopic functions.

Separate channels can also be used for the EXT-obturator andINT-obturator functions. As illustrated in FIG. 8E, one channel would beused for suction (via the INT-obturator) and a second dead-end channelwould be used for the force translation effects from the EXT-obturator.

For very long scopes (e.g., the enteroscope), three channels could beused to add a mid-scope distal pull effect such as the scope depicted inFIG. 8F. Separate channels could be used for the EXT-obturator andINT-obturator functions. As shown, one channel would be used for suction(via the INT-obturator), a second dead-end channel would be used for theforce translation effects from the EXT-obturator on the distal end ofthe scope, and a third channel that was dead-ended at mid-distance fromthe two ends of the scope would be used for an additional EXT-obturatorfor force translation effects on the middle section of the scope. (Forthe mid-scope effect to succeed, the dead-end of that channel needs tobe directly bonded to the external scope wall to mediate the distal-pulleffect.)

The systems of the present invention are not limited to endoscopes foruse in the colon; rather, the systems described above are also relevantto enteroscopes and to endoscopes for examination of other tubularorgans and structures. For example, the mechanisms described above forthe colonoscope can be, with some minor modifications, translateddirectly into use for automated rapid propelling of an enteroscopethrough the stomach, duodenum, jejunum and ileum. Its potential forimproving diagnostic and therapeutic approaches to the small bowel isclear. Miniaturized versions of the propelling mechanism of the presentinvention can be useful for advancing small catheters into: the gallbladder and hepato-biliary ducts; pancreatic ducts; ureters and kidneys;uterus and Fallopian tubes; and blood vessels of many organs. Enlargedversions of the propelling mechanism can be useful for non-medicalapplications such as advancing non-rigid instruments to identify andremedy disturbances of plumbing and fluid pumping systems, etc.

Having described preferred embodiments of a new and improved automatedself-propelling endoscope, it is believed that other modifications,variations and changes will be suggested to those skilled in the art inview of the teachings set forth herein. It is therefore to be understoodthat all such variations, modifications and changes are believed to fallwithin the scope of the present invention as defined by the appendedclaims. Although specific terms are employed herein, they are used in ageneric and descriptive sense only and not for purposes of limitation.

What is claimed is:
 1. A system for self-propelling a colonoscope withinan intestine comprising: a scope housing; an obturator channel disposedwithin and extending between proximal and distal ends of the scopehousing, wherein the obturator channel is secured to the scope housingsuch that movement of the obturator channel effects movement of thescope housing; an obturator disposed within the obturator channel andextending beyond the proximal end of the scope housing, wherein theobturator is secured to a section of the obturator channel at a securinglocation proximate the distal end of the scope housing; a bondingmechanism to releasably secure the obturator to the obturator channelsection: and a pull control device coupled to the obturator at acoupling location proximate the proximal end of the scope housing,wherein the pull control device is configured to apply a force upon theobturator at the coupling location to effect application of acorresponding pulling force on the obturator channel at the securinglocation and the distal end of the scope housing resulting in acorresponding movement of the distal end of the scope housing into theintestine that increases an intestinal path distance between the distalend of the scope housing and an insertion point of the scope housinginto the intestine.
 2. The system of claim 1, wherein the pull controldevice is further configured to control the force applied to theobturator to effect corresponding movement of the distal end of thescope housing in a direction that decreases the intestinal path distancebetween the distal end of the scope housing and the insertion point. 3.The system of claim 1, wherein the bonding mechanism includes aninflatable balloon surrounding an outer surface of the obturator.
 4. Thesystem of claim 1, further comprising: an internal obturator insertableand extendable between proximal and distal ends of the obturator; and afiberoptic channel disposed within and extending between the proximaland distal ends of the scope housing.
 5. The system of claim 1, furthercomprising: a push control device coupled to the scope housing aselected distance from the proximal end of the scope housing, whereinthe push control device is configured to apply a pushing force to thescope housing in a direction corresponding to the force applied to theobturator by the pull control device.
 6. The system of claim 5, whereinthe system prevents any movement of the proximal end of the scopehousing in response to the forces applied by the push and pull controldevices, the scope housing includes a looped section situated betweenthe push and pull control devices, and the looped section of the scopehousing decreases in length as the intestinal path distance between thedistal end of the scope housing and the insertion point is increased. 7.The colonoscope of claim 6, wherein each of the push and pull controldevices includes a supporting ring configured to support an end of thelooped section such that the scope housing is maintained at a desiredposition in relation to the push and pull control devices.
 8. Thecolonoscope of claim 5, wherein the pull control device includes aclamping element movable in relation to the pull control device andconfigured to releasably secure to the obturator, the push controldevice includes a clamping element movable in relation to the pushcontrol device and configured to releasably secure to the scope housing,and each of the push and pull control devices is further configured tocontrol movement and securement of the respective clamping device so asto effect application of a respective one of the pushing and pullingforces.
 9. The colonoscope of claim 8, wherein each clamping element ofthe push and pull control devices includes a first pair of opposingclamps and a second pair of opposing clamps spatially offset from thefirst pair of opposing clamps, and each of the push and pull controldevices is further configured to selectively alternate control ofmovement and securement between the respective first pair of opposingclamps and the respective second pair of opposing clamps to effectapplication of the respective one of the pushing and pulling forces. 10.A system for propelling a hollow probing member through a tunnel,wherein the probing member includes an internal member disposed withinand protruding from a proximal end of the probing member, the internalmember being releasably secured via a bonding mechanism to an internalsection of the probing member at a securing location proximate a distalend of the probing member, the system comprising: a pull control deviceincluding a coupling member securable to the internal member at acoupling location proximate the proximal end of the probing member,wherein the pull control device is configured to apply a force to theinternal member at the coupling location to effect application of apulling force at the distal end of the probing member resulting in acorresponding movement of the distal end of the probing member into thetunnel that increases a tunnel path distance between the distal end ofthe probing member and an insertion point of the probing member into thetunnel.
 11. The system of claim 10, wherein the pull control device isfurther configured to control the force applied to the internal memberto effect corresponding movement of the distal end of the probing memberin a direction that decreases the tunnel path distance between thedistal end of the probing member and the insertion point.
 12. The systemof claim 10, further comprising: a push control device including acoupling member securable to the probing member, wherein the pushcontrol device is configured to apply a pushing force to the probingmember in a direction corresponding to the pulling force applied to thedistal end of the probing member by the pull control device.
 13. Thesystem of claim 12, wherein each of the push and pull control devicesincludes a supporting ring configured to support a portion of theprobing member to maintain at a desired position of the probing memberin relation to the push and pull control devices.
 14. The system ofclaim 12, wherein the pull control device includes a clamping elementmovable in relation to the pull control device and configured toreleasably secure to the internal member, the push control deviceincludes a clamping element movable in relation to the push controldevice and configured to releasably secure to the probing member, andeach of the push and pull control devices is further configured tocontrol movement and securement of the respective clamping device so asto effect application of a respective one of the pushing and pullingforces.
 15. The system of claim 14, wherein each clamping element of thepush and pull control devices includes a first pair of opposing clampsand a second pair of opposing clamps spatially offset from the firstpair of opposing clamps, and each of the push and pull control devicesis further configured to selectively alternate control of movement andsecurement between the respective first pair of opposing clamps and therespective second pair of opposing clamps to effect application of therespective one of the pushing and pulling forces.
 16. The system ofclaim 10, wherein the probing member is a colonoscope, the internalmember is an obturator, and the coupling member of the pull controldevice is securable to the obturator.
 17. A method for propelling acolonoscope within an intestine of a subject, wherein the colonoscopeincludes a scope housing, an obturator channel disposed within andextending between proximal and distal ends of the scope housing, theobturator channel being secured to the scope housing such that movementof the obturator channel effects movement of the scope housing, and anobturator disposed within the obturator channel and extending beyond theproximal end of the scope housing, the obturator being releasablysecured, via a bonding mechanism, to a section of the obturator channelat a securing location proximate the distal end of the scope housing,the method comprising: (a) inserting the distal end of the scope housinginto the intestine of the subject at a selected insertion point; and (b)applying a force to the obturator at a location proximate the proximalend of the scope housing to effect a corresponding pulling force on theobturator channel at the securing location and the distal end of thescope housing, wherein the pulling force results in a correspondingmovement of the distal end of the scope housing within the intestinethat increases or decreases an intestinal path distance between thedistal end of the scope housing and the insertion point.
 18. The methodof claim 17, further comprising: (c) applying a force to the scopehousing at a selected distance from the proximal end of the scopehousing and in a direction corresponding to the force applied to theobturator.
 19. The method of claim 18, wherein (b) includes: (b.1)automatically applying the force to the obturator via a pull controldevice coupled to the obturator at the location proximate the proximalend of the scope housing; and wherein (c) includes: (c.1) automaticallyapplying the force to the scope housing via a push control devicecoupled to the scope housing at the selected distance from the proximalend of the scope housing.
 20. The method of claim 19, wherein the scopehousing includes a looped section disposed between the push and pullcontrol devices, and the method further comprises: (d) preventing anymovement of the proximal end of the scope housing in response to forcesapplied by the push and pull control devices in (b.1) and (c.1) suchthat, when the distal end of the scope housing is moved in a directionthat increases the intestinal path distance between the distal end ofthe scope housing and the insertion point, the looped section decreasesin length.
 21. The method of claim 20, further comprising: (e)supporting a first end of the looped section of the scope housing via afirst ring coupled to the pull control device, wherein the first endextends through the first ring; and (f) supporting a second end of thelooped section of the scope housing via a second ring coupled to thepush control device, wherein the second end extends through the secondring.
 22. The method of claim 19, wherein each of the push and pullcontrol devices includes a first and second pair of clamps to controlthe forces applied to the obturator and the scope housing, wherein eachpair of clamps is movable with respect to a respective one of the pushand pull control devices and is releasably securable to a respective oneof the obturator and the scope housing; and wherein (b.1) includes:(b.1.1) alternating control between the first pair of clamps and thesecond pair of clamps of the pull control device to apply the respectiveforce to the obturator; and wherein (b.2) includes: (b.2.1) alternatingcontrol between the first pair of clamps and the second pair of clampsof the push control device to apply the respective force to the scopehousing.
 23. A system for self-propelling a colonoscope within anintestine, the colonoscope including a scope housing and an obturatorextending within and protruding from a proximal end of the scopehousing, the obturator being releasably secured, via a bondingmechanism, to the scope housing at a location proximate the distal endof the scope housing, the system comprising: a means for applying aforce to the obturator at the proximal end of the scope housing thateffects a pulling movement of the distal end of the scope housing in adirection toward or away from an insertion point of the scope housingwithin the intestine.
 24. The system of claim 23, further comprising: ameans for applying a force to the scope housing in a direction thatcorresponds to the force applied to the obturator.
 25. A system forself-propelling a colonoscope within an intestine comprising: a scopehousing; an obturator channel disposed within and extending betweenproximal and distal ends of the scope housing, wherein the obturatorchannel is secured to the scope housing such that movement of theobturator channel effects movement of the scope housing; an obturatordisposed within the obturator channel and extending beyond the proximalend of the scope housing, wherein the obturator is secured to a sectionof the obturator channel at a securing location proximate the distal endof the scope housing; an internal obturator insertable and extendablebetween proximal and distal ends of the obturator; and a fiberopticchannel disposed within and extending between the proximal and distalends of the scope housing; and a pull control device coupled to theobturator at a coupling location proximate the proximal end of the scopehousing, wherein the pull control device is configured to apply a forceupon the obturator at the coupling location to effect application of acorresponding pulling force on the obturator channel at the securinglocation and the distal end of the scope housing resulting in acorresponding movement of the distal end of the scope housing into theintestine that increases an intestinal path distance between the distalend of the scope housing and an insertion point of the scope housinginto the intestine.
 26. The system of claim 5, wherein the scope housingincludes a looped section situated between the push and pull controldevices, and the proximal end of the scope housing and the loopedsection of the scope housing are suitably anchored to control the lengthof the looped section such that there is no increase in the length ofthe looped section when forces are applied by the push and pull controldevices.
 27. The method of claim 19, wherein the scope housing includesa looped section disposed between the push and pull control devices, andthe method further comprises: (d) suitably anchoring the proximal end ofthe scope housing and the looped section to prevent any increase in thelength of the looped section when forces are applied by the push andpull control devices in (b.1) and (c.1).